1. Field of the Invention
This invention relates generally to a fuel system for an internal combustion engine and more particularly to method and apparatus for expanding the fuel in the fuel system thereby increasing the combustion of the fuel.
2. Description of the Prior Art
It is well known in the art of fuel delivery systems for internal combustion engines that the temperature of fuel delivered to the engine's carburetor or fuel injection system is directly proportional to the efficiency with which the fuel is burned.
As shown in U.S. Pat. No. 4,841,943, fuel which is heated above its ambient temperature tends to vaporize more completely upon introduction into the intake manifold of the engine. The vaporization of the fuel causes the fuel to break down or expand into finely divided fuel molecules each having a surface capable of bonding with oxygen injected with the fuel system. Since it is the oxygen mixed with the fuel which causes the combustion of the fuel, the greater adhesion between fuel molecules and oxygen, the greater the fuel combustion. As fuel combustion increases, the pollutants exhausted by the engine are decreased and the engine runs for a longer duration on a given quantity of fuel. Fuel unused by the vehicle engine is returned to the fuel tank via a fuel return line for recirculation through the delivery system.
U.S. Pat. No. 4,841,943 discloses utilizing engine coolant as a source of heat to increase the temperature of the fuel. The fuel is pumped under pressure from the fuel tank into a heating chamber. A copper coil is present in the chamber and an adjustable quantity of engine coolant is run through the coil to elevate the temperature of the fuel in the heating chamber above its ambient temperature boiling point. The superheated fuel then passes through the chamber and into the fuel injection system of the vehicle.
U.S. Pat. No. 5,596,973 discloses a fuel expanding device in which fuel is directed by the fuel pump from the vehicle fuel tank through a mesh flow conditioning device and into a copper coil. The coil surrounds a portion of the radiator hose and the temperature from the radiator hose elevates the temperature of the fuel passing through the coil. The heated fuel is then passed along to the fuel injection system for combustion by the engine. Additional examples of known fuel heating devices are shown in U.S. Pat. Nos. 3,253,647; 4,434,774; 4,858,584; 4,436,075; 5,443,053; 4,883,040; 5,411,005; 5,005,551; 5,219,399; 4,002,173; 4,048,969; 4,539,966; 4606,319; and 5,515,814.
Although various fuel preheating devices and methods have been constructed and incorporated into internal combustion engines with the intention of increasing fuel combustion, many of these devices have proven to be ineffective mainly due to expense, complexity, and inefficiency. The above-identified devices do not provide a cost effective, simple, and functional method for maximizing fuel temperature prior to introduction into a fuel injection system.
Therefore, there is a need for a fuel expanding device which maximizes the temperature of fuel prior to combustion in the vehicle engine.